This is a nickname given to the stomping of the feet surfers (and now swimmers) employ when entering the ocean in HB.
They do this to signify they belong in the cult.
They do this to prevent stingrays from stinging them. The thinking goes that stomping, or stamping, your feet on the sand as you enter the water alerts the stingrays to your presence. You’ll want to do this as you enter the water, all the way until you’re in deep enough water to start swimming.
From my own experience, almost all my neighbors who are surfers have been stung. These hardy men have likened the pain to being stabbed. Repeatedly. For about 4 hours.
I’m not one to test such theories. I, too, do the HB Shuffle. When entering and exiting the ocean.